A steamed former Gracie Mansion chef unloaded on First Lady Chirlane McCray Tuesday, mocking her attitude after she called him a “servant.”

“Maybe Ms. de Blasio is watching too much ‘Downton Abbey,’ ” fumed Mitchel London, who once cooked for former Mayor Ed Koch.

“Nobody in this industry uses that word. If that’s the way [she thinks] — and clearly it is, because she came up with that word — let me say I’m just glad I’m not at Gracie now.”

London said he was “stunned” by the characterization. “It really is just a little ignorant in this day and age,” he said.

The first lady drew sharp criticism Tuesday after explaining to a reporter how she planned to use the Gracie Mansion attic when her family moves in: “I can convey to you, with confidence, there will not be a servant living there.”

London was the attic’s only resident — having lived in a one-bedroom attic apartment there when he worked for Koch.

London is now a chef at the Fairway Café restaurant on the Upper West Side.

“At Fairway, if I were to use that word about an employee, I’d be in HR the same day! You cannot say that stuff. And there’s not many words you can’t say, but the S-word is one of them.”

“It’s a harsh word. Harsh. It shows a lack of something,” London blasted. “It’s ridiculous.”

McCray’s spokeswoman refused to comment on the controversial word choice.

The chef said he loved being part of Koch’s staff.

Asked how the former mayor treated employees, he said, “What’s the polar opposite of ‘servant’? Whatever it is, that was Ed.”

London also blasted what he sees as McCray’s disdain for household workers, saying, “What does she think? That there are no people cleaning it, maintaining it, dusting it? It happened by itself?”

“Maybe she wants to run the house herself — no staff, no ‘servants.’ Big job for one lady,” he cracked.

Asked if he had ever wanted to work for anyone but Koch, London said, “I would not have boiled water for another mayor.”

London left Gracie Mansion before Koch finished his third term, after an investigation found he had improperly used Gracie co-workers and supplies for a private catering business.

London on Tuesday denied having used the mansion’s supplies, but said he did hire Gracie co-workers on their off hours. He said the city told him he could not do both jobs.